One of the most important design variables in ammunition development is the performance of a cartridge over the operating temperature range. This performance is currently limited by the operating pressure at hot temperatures.
Attempts to improve cartridge performance over a range of temperatures have typically relied on mechanical devices and propellant innovations. Propellant design, for example, has long focused on chemically creating a propellant to reduce performance differences over temperature. A mechanical design which has been explored uses control tube concepts to modify the initial travel of the projectile as a function of temperature using material thermal expansion or bimetallic strips.
In contrast, the instant invention provides an ignition system known as a Smart Cartridge Ignition System, described hereinbelow, that controls the performance of a cartridge so that it is substantially invariant over ambient and cold temperature ranges.